When available capacity of a storage device or other limited-capacity entity drops below a threshold value, quick response can be essential in order to avoid performance degradation or a catastrophic failure of an application or hardware device that depends upon the availability of sufficient capacity. It is thus important to be able to predict overutilization of such a limited-capacity entity before it is too late to prevent or mitigate such a problem or failure.
Such prediction can be difficult, however, because an amount of free space of a storage unit can change abruptly, with a degree of randomness, or in an other way that is not easily predictable as a function of current utilization.